F.J. de Heer, B.F.J. Luyken, D. Jaecks and L. Wolterbeek Muller, Excitation of Ne, Ar, Kr and Xe by He+ impact (0.3-10 keV), Physica 41, 588-600 (1969)
F.W.E. Knoop, J. Kistemaker and L.J. Oosterhoff, Low energy electron impact excitation spectra of 1, 3, 5-cycloheptatriene and 1, 3, 5, 7-cyclo-octatetraene, Chem. Phys. Lett. 3, 73-77 (1969)
A.P.M. Baede, M.C. Moutinho, A.E. de Vries and J.H. Los, Total cross sections for charge transfer between alkali atoms and halogen molecules, Chem. Phys. Lett. 3, 530-531 (1969)
J.W.R. Fennema, On the impact of protons on hydrogen atoms. I Introduction. The parametric treatment and the derivation of some of its properties, Physica 43, 375-400 (1969)